The invention relates in general to a spool, and more particularly, is directed to a spool or warp beam used in the textile industry.
Such spools onto which threads are warped are already known, being used in conventional knitting looms. The prior art spools or warp beams generally consist of cylindrical drums which are fitted to two annular, lateral flanges by means of brackets. The brackets are usually each provided with a screw threaded portion which is screwed onto the threaded part at the two ends of the drum.
Since these spools are subjected to considerable deformation and fatigue stress on account of radial and horizontal forces of the tension components of the warped threads, consideration was given to making the spools or warp beams of two different materials with two different moduli of elasticity. In this manner, they should be able to better withstand the tensions of the warped threads and that the deformation, particularly that of the flanges, should be reduced to a minimum. It will be noted that the thread makes contact with the flanges which are made of light alloy, having a modulus of elasticity of, for example, 7,000. These light alloy flanges are supported by steel brackets, made of steel with a modulus of elasticity of 24,000, which appreciably reduces the deformations of the flanges inversely proportionally to the modulus.
Although this type of design insures resistance against fatigue generated by the tensions resulting from the load of the thread, that is to say, that although it takes the mechanical deformations of the loaded spools into account, it does not take into consideration other deformations, which are just as serious, which can be caused by shocks received during handling of empty or loaded spools. Thus, it will be realized that during use, the outer portions of the spools are frequently damaged as a result of falls or blows, which results in their deformation in a direction opposite to that of the load from a horizontal stress directed outwardly. Blows from outside result in the flanges being pinched, which leads to their buckling or removal from the steel bracket. This buckling of the flange with respect to the axis of the drum of the spool is a primary reason for taking the spool out of service, as otherwise, the buckling would lead to the rupture or the untimely displacement of the warp threads located on the warp beam, in parallel, sided by side relation, according to the place they will occupy in the cloth.